The present invention relates generally to edge card connectors, and more particularly to connectors that utilize flexible circuitry as the connector contacts and which have increased compliance.
Connectors are well known in the art which provide a connection between a primary circuit board and a secondary circuit board and are commonly referred to in the art as edge card connectors. These connectors typically include an insulative housing having a slot extending lengthwise within the housing that receives an edge of the secondary circuit card and a plurality of contacts on opposing sides of the slot. These contacts are typically stamped and formed and thus such connectors are limited in their "pitch", i.e., the spacing between the contacts. Where the connector contacts are stamped and formed, the stamping and forming process limits the pitch that can be obtained to about 0.5 mm.
By using flexible circuitry for the contacts, smaller pitches of about 0.3 mm may be obtained. U.S. Pat. No. 5,679,018 issued October describes a card connector utilizing flexible circuitry and having a circuit card-engaging means that applies and maintains a contact force on the conductive traces that are formed on the circuit card. Although reliable, it has been discovered that this connector construction may possess some inherent disadvantages in its compliance aspect. For example, in such a connector, a solid ground plane is typically formed as part of the flexible circuitry, and signal circuitry is laid over the ground plane, but the ground plane ends before the interconnection interface areas. Were the ground plane to be continued into the interconnection areas, the solid characteristic of the ground plane would act to stiffen the flexible circuitry thereat and reduce the compliance aspect of the connector where it sometimes cannot fully mate with opposing contacts formed on the circuit board to which the connector is mounted in instances where there are variations in the circuit board.
Accordingly, a need for a flexible circuitry connector having increased compliance and improved ground plane areas exists.